title: Short-term synaptic plasticity and intensity coding.
abstract: Alterations in synaptic strength over short time scales, termed short-term synaptic plasticity, can gate the flow of information through neural circuits. Different information can be extracted from the same presynaptic spike train depending on the activity- and time-dependent properties of the plasticity at a given synapse. The parallel processing in the brain stem auditory pathways provides an excellent model system for investigating the functional implications of short-term plasticity in neural coding. We review recent evidence that short-term plasticity differs in different pathways with a special emphasis on the 'intensity' pathway. While short-term depression dominates the 'timing' pathway, the intensity pathway is characterized by a balance of short-term depression and facilitation that allows linear transmission of rate-coded intensity information. Target-specific regulation of presynaptic plasticity mechanisms underlies the differential expression of depression and facilitation. The potential contribution of short-term plasticity to different aspects of 'intensity'-related information processing, such as interaural level/intensity difference coding, amplitude modulation coding, and intensity-dependent gain control coding, is discussed.
authors.affiliation: Department of Biology, University of Maryland, College Park, MD 20742, USA. macleod@umd.edu
authors.forename: Katrina M
authors.initials: KM
authors.lastname: MacLeod
mesh_terms: D000818:Animals; D001306:Auditory Pathways / Q000473:pathology; D001369:Axons / Q000473:pathology; D001931:Brain Mapping / Q000379:methods; D001933:Brain Stem / Q000473:pathology / Q000502:physiology*; D017626:Cochlear Nucleus / Q000473:pathology; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000378:metabolism; D017470:Receptors, Glutamate / Q000378:metabolism; D013569:Synapses / Q000378:metabolism*; D055366:Synaptic Potentials; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: D017470:Receptors, Glutamate